/*
 * Copyright (c) 2018 Goldman Sachs and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Eclipse Distribution License v. 1.0 which accompany this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 */

package org.eclipse.collections.impl.bag.immutable;

import java.io.IOException;
import java.io.Serializable;
import java.util.Collection;
import java.util.Comparator;
import java.util.Iterator;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Optional;

import org.eclipse.collections.api.LazyIterable;
import org.eclipse.collections.api.RichIterable;
import org.eclipse.collections.api.bag.Bag;
import org.eclipse.collections.api.bag.ImmutableBag;
import org.eclipse.collections.api.bag.MutableBag;
import org.eclipse.collections.api.bag.MutableBagIterable;
import org.eclipse.collections.api.bag.primitive.ImmutableBooleanBag;
import org.eclipse.collections.api.bag.primitive.ImmutableByteBag;
import org.eclipse.collections.api.bag.primitive.ImmutableCharBag;
import org.eclipse.collections.api.bag.primitive.ImmutableDoubleBag;
import org.eclipse.collections.api.bag.primitive.ImmutableFloatBag;
import org.eclipse.collections.api.bag.primitive.ImmutableIntBag;
import org.eclipse.collections.api.bag.primitive.ImmutableLongBag;
import org.eclipse.collections.api.bag.primitive.ImmutableShortBag;
import org.eclipse.collections.api.bag.sorted.MutableSortedBag;
import org.eclipse.collections.api.block.function.Function;
import org.eclipse.collections.api.block.function.Function0;
import org.eclipse.collections.api.block.function.Function2;
import org.eclipse.collections.api.block.function.primitive.BooleanFunction;
import org.eclipse.collections.api.block.function.primitive.ByteFunction;
import org.eclipse.collections.api.block.function.primitive.CharFunction;
import org.eclipse.collections.api.block.function.primitive.DoubleFunction;
import org.eclipse.collections.api.block.function.primitive.FloatFunction;
import org.eclipse.collections.api.block.function.primitive.IntFunction;
import org.eclipse.collections.api.block.function.primitive.LongFunction;
import org.eclipse.collections.api.block.function.primitive.ObjectIntToObjectFunction;
import org.eclipse.collections.api.block.function.primitive.ShortFunction;
import org.eclipse.collections.api.block.predicate.Predicate;
import org.eclipse.collections.api.block.predicate.Predicate2;
import org.eclipse.collections.api.block.predicate.primitive.IntPredicate;
import org.eclipse.collections.api.block.procedure.Procedure;
import org.eclipse.collections.api.block.procedure.Procedure2;
import org.eclipse.collections.api.block.procedure.primitive.ObjectIntProcedure;
import org.eclipse.collections.api.list.MutableList;
import org.eclipse.collections.api.map.ImmutableMap;
import org.eclipse.collections.api.map.MutableMap;
import org.eclipse.collections.api.map.sorted.MutableSortedMap;
import org.eclipse.collections.api.multimap.bag.ImmutableBagMultimap;
import org.eclipse.collections.api.ordered.OrderedIterable;
import org.eclipse.collections.api.partition.bag.PartitionImmutableBag;
import org.eclipse.collections.api.set.ImmutableSet;
import org.eclipse.collections.api.set.MutableSet;
import org.eclipse.collections.api.tuple.Pair;
import org.eclipse.collections.impl.EmptyIterator;
import org.eclipse.collections.impl.bag.mutable.HashBag;
import org.eclipse.collections.impl.bag.sorted.mutable.TreeBag;
import org.eclipse.collections.impl.block.factory.Comparators;
import org.eclipse.collections.impl.factory.Bags;
import org.eclipse.collections.impl.factory.Lists;
import org.eclipse.collections.impl.factory.Maps;
import org.eclipse.collections.impl.factory.Sets;
import org.eclipse.collections.impl.factory.primitive.BooleanBags;
import org.eclipse.collections.impl.factory.primitive.ByteBags;
import org.eclipse.collections.impl.factory.primitive.CharBags;
import org.eclipse.collections.impl.factory.primitive.DoubleBags;
import org.eclipse.collections.impl.factory.primitive.FloatBags;
import org.eclipse.collections.impl.factory.primitive.IntBags;
import org.eclipse.collections.impl.factory.primitive.LongBags;
import org.eclipse.collections.impl.factory.primitive.ShortBags;
import org.eclipse.collections.impl.map.mutable.UnifiedMap;
import org.eclipse.collections.impl.map.sorted.mutable.TreeSortedMap;
import org.eclipse.collections.impl.multimap.bag.HashBagMultimap;
import org.eclipse.collections.impl.partition.bag.PartitionHashBag;
import org.eclipse.collections.impl.utility.ArrayIterate;
import org.eclipse.collections.impl.utility.Iterate;
import org.eclipse.collections.impl.utility.LazyIterate;

This is a zero element ImmutableBag which is created by calling the Bags.immutable.empty().
Since:1.0
/** * This is a zero element {@link ImmutableBag} which is created by calling the Bags.immutable.empty(). * * @since 1.0 */
final class ImmutableEmptyBag<T> extends AbstractImmutableBag<T> implements Serializable { static final ImmutableBag<?> INSTANCE = new ImmutableEmptyBag<>(); private static final long serialVersionUID = 1L; private static final LazyIterable<?> LAZY_ITERABLE = LazyIterate.adapt(INSTANCE); private static final Object[] TO_ARRAY = new Object[0]; private static final PartitionImmutableBag<Object> IMMUTABLE_EMPTY_PARTITION = new PartitionHashBag<>().toImmutable(); @Override public boolean equals(Object obj) { if (obj == this) { return true; } return obj instanceof Bag && ((Bag<?>) obj).isEmpty(); } @Override public int sizeDistinct() { return 0; } @Override public int occurrencesOf(Object item) { return 0; } @Override public void forEachWithOccurrences(ObjectIntProcedure<? super T> objectIntProcedure) { } @Override public <V> ImmutableBag<V> collectWithOccurrences(ObjectIntToObjectFunction<? super T, ? extends V> function) { return Bags.immutable.empty(); }
Since:9.1.
/** * @since 9.1. */
@Override public <V, R extends Collection<V>> R collectWithOccurrences(ObjectIntToObjectFunction<? super T, ? extends V> function, R target) { return target; } @Override public MutableMap<T, Integer> toMapOfItemToCount() { return Maps.mutable.empty(); } @Override public int hashCode() { return 0; } @Override public int size() { return 0; } @Override public boolean isEmpty() { return true; } @Override public boolean notEmpty() { return false; } @Override public boolean contains(Object object) { return false; } @Override public boolean containsAllIterable(Iterable<?> source) { return Iterate.isEmpty(source); } @Override public boolean containsAllArguments(Object... elements) { return ArrayIterate.isEmpty(elements); } @Override public ImmutableBag<T> tap(Procedure<? super T> procedure) { return this; } @Override public void each(Procedure<? super T> procedure) { } @Override public void forEachWithIndex(ObjectIntProcedure<? super T> objectIntProcedure) { } @Override public <P> void forEachWith(Procedure2<? super T, ? super P> procedure, P parameter) { } @Override public T getFirst() { return null; } @Override public T getLast() { return null; } @Override public T getOnly() { throw new IllegalStateException("Size must be 1 but was " + this.size()); } @Override public Iterator<T> iterator() { return EmptyIterator.getInstance(); } @Override public ImmutableBag<T> newWith(T element) { return Bags.immutable.with(element); } @Override public ImmutableBag<T> newWithout(T element) { return this; } @Override public ImmutableBag<T> newWithAll(Iterable<? extends T> elements) { MutableBag<T> bag = HashBag.newBag(elements); return bag.toImmutable(); } @Override public ImmutableBag<T> selectByOccurrences(IntPredicate predicate) { return this; } @Override public ImmutableBag<T> select(Predicate<? super T> predicate) { return this; } @Override public <P> ImmutableBag<T> selectWith(Predicate2<? super T, ? super P> predicate, P parameter) { return this; } @Override public ImmutableBag<T> reject(Predicate<? super T> predicate) { return this; } @Override public <P> ImmutableBag<T> rejectWith(Predicate2<? super T, ? super P> predicate, P parameter) { return this; } @Override public PartitionImmutableBag<T> partition(Predicate<? super T> predicate) { return (PartitionImmutableBag<T>) IMMUTABLE_EMPTY_PARTITION; } @Override public <P> PartitionImmutableBag<T> partitionWith(Predicate2<? super T, ? super P> predicate, P parameter) { return (PartitionImmutableBag<T>) IMMUTABLE_EMPTY_PARTITION; } @Override public <S> ImmutableBag<S> selectInstancesOf(Class<S> clazz) { return (ImmutableBag<S>) INSTANCE; } @Override public <V> ImmutableBag<V> collect(Function<? super T, ? extends V> function) { return (ImmutableBag<V>) INSTANCE; } @Override public ImmutableBooleanBag collectBoolean(BooleanFunction<? super T> booleanFunction) { return BooleanBags.immutable.empty(); } @Override public ImmutableByteBag collectByte(ByteFunction<? super T> byteFunction) { return ByteBags.immutable.empty(); } @Override public ImmutableCharBag collectChar(CharFunction<? super T> charFunction) { return CharBags.immutable.empty(); } @Override public ImmutableDoubleBag collectDouble(DoubleFunction<? super T> doubleFunction) { return DoubleBags.immutable.empty(); } @Override public ImmutableFloatBag collectFloat(FloatFunction<? super T> floatFunction) { return FloatBags.immutable.empty(); } @Override public ImmutableIntBag collectInt(IntFunction<? super T> intFunction) { return IntBags.immutable.empty(); } @Override public ImmutableLongBag collectLong(LongFunction<? super T> longFunction) { return LongBags.immutable.empty(); } @Override public ImmutableShortBag collectShort(ShortFunction<? super T> shortFunction) { return ShortBags.immutable.empty(); } @Override public <P, V> ImmutableBag<V> collectWith(Function2<? super T, ? super P, ? extends V> function, P parameter) { return (ImmutableBag<V>) INSTANCE; } @Override public <V> ImmutableBag<V> collectIf( Predicate<? super T> predicate, Function<? super T, ? extends V> function) { return (ImmutableBag<V>) INSTANCE; } @Override public <V> ImmutableBag<V> flatCollect(Function<? super T, ? extends Iterable<V>> function) { return (ImmutableBag<V>) INSTANCE; }
Since:9.0
/** * @since 9.0 */
@Override public <V> ImmutableBag<V> countBy(Function<? super T, ? extends V> function) { return Bags.immutable.empty(); }
Since:9.0
/** * @since 9.0 */
@Override public <V, R extends MutableBagIterable<V>> R countBy(Function<? super T, ? extends V> function, R target) { return target; }
Since:9.0
/** * @since 9.0 */
@Override public <V, P> ImmutableBag<V> countByWith(Function2<? super T, ? super P, ? extends V> function, P parameter) { return Bags.immutable.empty(); }
Since:9.0
/** * @since 9.0 */
@Override public <V, P, R extends MutableBagIterable<V>> R countByWith(Function2<? super T, ? super P, ? extends V> function, P parameter, R target) { return target; }
Since:10.0.0
/** * @since 10.0.0 */
@Override public <V> ImmutableBag<V> countByEach(Function<? super T, ? extends Iterable<V>> function) { return Bags.immutable.empty(); }
Since:10.0.0
/** * @since 10.0.0 */
@Override public <V, R extends MutableBagIterable<V>> R countByEach(Function<? super T, ? extends Iterable<V>> function, R target) { return target; } @Override public <V> ImmutableBagMultimap<V, T> groupBy(Function<? super T, ? extends V> function) { // TODO: Create a Singleton ImmutableEmptyBagMultimap for efficiency return HashBagMultimap.<V, T>newMultimap().toImmutable(); } @Override public <V> ImmutableBagMultimap<V, T> groupByEach(Function<? super T, ? extends Iterable<V>> function) { // TODO: Create a Singleton ImmutableEmptyBagMultimap for efficiency return HashBagMultimap.<V, T>newMultimap().toImmutable(); } @Override public <V> ImmutableMap<V, T> groupByUniqueKey(Function<? super T, ? extends V> function) { return Maps.immutable.empty(); } @Override public T detect(Predicate<? super T> predicate) { return null; } @Override public <P> T detectWith(Predicate2<? super T, ? super P> predicate, P parameter) { return null; } @Override public Optional<T> detectOptional(Predicate<? super T> predicate) { return Optional.empty(); } @Override public <P> Optional<T> detectWithOptional(Predicate2<? super T, ? super P> predicate, P parameter) { return Optional.empty(); } @Override public T detectIfNone(Predicate<? super T> predicate, Function0<? extends T> function) { return function.value(); } @Override public <P> T detectWithIfNone(Predicate2<? super T, ? super P> predicate, P parameter, Function0<? extends T> function) { return function.value(); } @Override public int count(Predicate<? super T> predicate) { return 0; } @Override public <P> int countWith(Predicate2<? super T, ? super P> predicate, P parameter) { return 0; } @Override public boolean anySatisfy(Predicate<? super T> predicate) { return false; } @Override public boolean allSatisfy(Predicate<? super T> predicate) { return true; } @Override public boolean noneSatisfy(Predicate<? super T> predicate) { return true; } @Override public <P> boolean anySatisfyWith(Predicate2<? super T, ? super P> predicate, P parameter) { return false; } @Override public <P> boolean allSatisfyWith(Predicate2<? super T, ? super P> predicate, P parameter) { return true; } @Override public <P> boolean noneSatisfyWith(Predicate2<? super T, ? super P> predicate, P parameter) { return true; } @Override public <IV> IV injectInto(IV injectedValue, Function2<? super IV, ? super T, ? extends IV> function) { return injectedValue; } @Override public MutableList<T> toList() { return Lists.mutable.empty(); } @Override public MutableList<T> toSortedList() { return Lists.mutable.empty(); } @Override public MutableList<T> toSortedList(Comparator<? super T> comparator) { return Lists.mutable.empty(); } @Override public <V extends Comparable<? super V>> MutableList<T> toSortedListBy(Function<? super T, ? extends V> function) { return Lists.mutable.empty(); } @Override public MutableSet<T> toSet() { return Sets.mutable.empty(); } @Override public MutableBag<T> toBag() { return Bags.mutable.empty(); } @Override public MutableSortedBag<T> toSortedBag() { return TreeBag.newBag(); } @Override public MutableSortedBag<T> toSortedBag(Comparator<? super T> comparator) { return TreeBag.newBag(comparator); } @Override public <V extends Comparable<? super V>> MutableSortedBag<T> toSortedBagBy(Function<? super T, ? extends V> function) { return TreeBag.newBag(Comparators.byFunction(function)); } @Override public <NK, NV> MutableMap<NK, NV> toMap( Function<? super T, ? extends NK> keyFunction, Function<? super T, ? extends NV> valueFunction) { return UnifiedMap.newMap(); } @Override public <NK, NV, R extends Map<NK, NV>> R toMap( Function<? super T, ? extends NK> keyFunction, Function<? super T, ? extends NV> valueFunction, R target) { return target; } @Override public <NK, NV> MutableSortedMap<NK, NV> toSortedMap( Function<? super T, ? extends NK> keyFunction, Function<? super T, ? extends NV> valueFunction) { return TreeSortedMap.newMap(); } @Override public <NK, NV> MutableSortedMap<NK, NV> toSortedMap( Comparator<? super NK> comparator, Function<? super T, ? extends NK> keyFunction, Function<? super T, ? extends NV> valueFunction) { return TreeSortedMap.newMap(comparator); } @Override public <KK extends Comparable<? super KK>, K, V> MutableSortedMap<K, V> toSortedMapBy(Function<? super K, KK> sortBy, Function<? super T, ? extends K> keyFunction, Function<? super T, ? extends V> valueFunction) { return TreeSortedMap.newMap(Comparators.byFunction(sortBy)); } @Override public LazyIterable<T> asLazy() { return (LazyIterable<T>) LAZY_ITERABLE; } @Override public Object[] toArray() { return TO_ARRAY; } @Override public <T> T[] toArray(T[] a) { if (a.length > 0) { a[0] = null; } return a; } @Override public T min(Comparator<? super T> comparator) { throw new NoSuchElementException(); } @Override public T max(Comparator<? super T> comparator) { throw new NoSuchElementException(); } @Override public T min() { throw new NoSuchElementException(); } @Override public T max() { throw new NoSuchElementException(); } @Override public <V extends Comparable<? super V>> T minBy(Function<? super T, ? extends V> function) { throw new NoSuchElementException(); } @Override public <V extends Comparable<? super V>> T maxBy(Function<? super T, ? extends V> function) { throw new NoSuchElementException(); } @Override public String toString() { return "[]"; } @Override public String makeString() { return ""; } @Override public String makeString(String separator) { return ""; } @Override public String makeString(String start, String separator, String end) { return start + end; } @Override public void appendString(Appendable appendable) { } @Override public void appendString(Appendable appendable, String separator) { } @Override public void appendString(Appendable appendable, String start, String separator, String end) { try { appendable.append(start); appendable.append(end); } catch (IOException e) { throw new RuntimeException(e); } }
Deprecated:in 6.0. Use OrderedIterable.zip(Iterable) instead.
/** * @deprecated in 6.0. Use {@link OrderedIterable#zip(Iterable)} instead. */
@Override @Deprecated public <S> ImmutableBag<Pair<T, S>> zip(Iterable<S> that) { return Bags.immutable.empty(); }
Deprecated:in 6.0. Use OrderedIterable.zipWithIndex() instead.
/** * @deprecated in 6.0. Use {@link OrderedIterable#zipWithIndex()} instead. */
@Override @Deprecated public ImmutableSet<Pair<T, Integer>> zipWithIndex() { return Sets.immutable.empty(); } @Override public RichIterable<RichIterable<T>> chunk(int size) { if (size <= 0) { throw new IllegalArgumentException("Size for groups must be positive but was: " + size); } return Bags.immutable.empty(); } private Object writeReplace() { return new ImmutableBagSerializationProxy<>(this); } @Override public ImmutableSet<T> selectUnique() { return Sets.immutable.empty(); } }